Device for spreading a bituminous coating from a film of determined width of the coating, and method for implementing same

ABSTRACT

The device includes a unit for moving on the ground along a longitudinal direction of advance ( 32 ) and a spreading unit fed with bituminous coating by a feeding unit and adapted to spread during the displacement of the device the layer of bituminous coating over a determined width of the ground considered transversally to the direction of advance. The spreading unit is adapted to perform the rolling, the crumbling and the falling down to the ground of the bituminous coating.

The present invention relates to a device for spreading a bituminouscoating into a small thickness layer, called a film, as well as a methodfor implementing this device. It finds applications in the field ofpublic works, and in particular the construction of circulating lanesor, particularly advantageously, the maintenance or reconditioningthereof.

A coating (or bituminous coating) is a mixture of gravels, sand andhydro-carbonated binder (commonly called “asphalt”) applied into one orseveral layers to form the road pavement. Conventionally, the depositionof a layer of coating may be performed according to different modes. Itis hence possible to make the distinction between the hot coatingshaving a temperature higher than 130° C., the warm coatings having atemperature between 100° C. and 130° C., the half-warm coatings having atemperature between 85° C. and 100° C., the cold dense coatings, thecold open coatings or the emulsion gravels, which all forms “coatings”within the meaning of the present document.

Currently, the deposition of a layer of coating is performed byadjustment of the layer directly on the support, which is generally theground or a sub-layer of coating. The adjustment is performed by means,either of a smoothing table such as a finisher table or a fastintervention finisher table (FIR), or a blade such as a levelling blade.These working means are tributary of the quality of the support that isto receive said layer. This support quality is characterized by the moreor less marked presence of longitudinal deformations, transversedeformations, depressions, the different surface textures, i.e. smooth,much roughened, fat or thin support, etc. Such heterogeneities do notallow a good control of the dosage nor a correct smoothing of thecoating deposited to form the layer, and this is all the more impactingthat the deformations are great or that the working thicknesses aresmall, in particular when the layer thickness is lower than 3 cm.

The conventional methods of spreading bituminous coatings on the groundimplement automotive machines, called finishers, which include, at therear with respect to their direction of advance, a means for depositingand distributing transversally, in the width direction, on the ground,the bituminous coating, followed, more on the rear, by a smoothing tableintended to perform a levelled surface layer. Vibrating means intendedto facilitate the distribution and to pack down the layer are alsoimplemented. Possibly, a ramp for spraying on the ground a bondingand/or sealing layer may be implemented upstream from the deposition ofthe bituminous coating on the ground. A tank of bituminous coating isinstalled at the front of the machine and this tank may be continuouslyfed, at the rear of the truck whose bituminous coating dump isdischarged into the tank. A conveying line allows to convey thebituminous coating from the tank, on the front, towards the rear of themachine, where it is deposited on the ground. The machine includestracks for its displacement on the ground, or tires, and means forcontrolling its displacements and its various members. In particular,control means allow an automation and adjustment of the making of thebituminous coating layer.

With this method, the bituminous coating is deposited directly on theground and is thereafter levelled to form a layer of a certain width andthickness. The height of the layer, and hence the thickness thereof,depend on the position in height, of the angle of attack, of thesmoothing table. The latter is integral with the automotive machine andhence follows the movements of the machine in its displacement, and inparticular, the untimely movements due to the deformations of the groundsurface. These untimely movements may be more or less important as afunction of the deformations of the ground on which the machine moves,wherein such movements may even be amplified as a function of the leverarm between the machine and the smoothing table. In order to limit thelayer surface irregularities that would result therefrom, it is possibleto implement means for correcting these untimely movements due to thedeformations of the ground. However, given that the smoothing table is arigid bar, it is not possible to correct all the effects of theseuntimely movements.

Another drawback of this method resides in the fact that it is notpossible to obtain a layer of low thickness because if the smoothingtable is too much lowered, the distribution of the coating over theground risks to be deteriorated, for example with a risk of tearing outof the bituminous coating, or in case of deformation of the ground underthe machine or under the levelling blade, of friction of the levellingblade on the ground.

Finally, with this method, the quantity of bituminous coating in thelayer, at any point of the ground, cannot be controlled accurately.Indeed, if there is a recess in the ground, the bituminous coating fillsit up to the level of the layer surface, which is in practice at thesame absolute height as all around the recess and there will hence bemore bituminous coating at the vertical of such a recess than elsewhere.This will be the opposite at the level of a boss of the ground, withless bituminous coating, not to mention the risk that the smoothingtable knocks said boss if it is attempted to make a layer of lowthickness.

This method must hence preferably be executed after a sufficientpreparation of the ground, in particular the levelling thereof.Moreover, it leads to make layers of relatively high thickness and forwhich it is in practice impossible to have an accurate control of thequantity of bituminous coating spread by surface unit.

The present invention proposes to remedy in particular these drawbacksby using a method for spreading with a spreading device, in which adosage of the bituminous coating is made before the deposition to theground. Thanks to that, a determined quantity of bituminous coating isdeposited on the ground. The so-obtained layer includes a determinedquantity of bituminous coating that is constant in any point of itssurface and whatever the deformations of the ground surface on which thelayer is spread. It then becomes possible to obtain a layer of muchreduced thickness, which is particularly interesting in the case ofcirculation lane reconditioning or on adapted supports.

It will be seen that it is possible to use two means for performing thisdosage, either by making a bituminous coating film of determinedthickness between two cylinders, or by making an extended bituminouscoating film of determined thickness on an endless belt. In both cases,the bituminous coating film is then crumbled and falls, in particular bybeing projected, down to the ground. In the first case, it can beconsidered that the film that is created is almost immediately crumbledbecause that are the same cylinders that both make the film (control ofthe quantity of material) and then crumble the film. In the second case,the film has a longer material existence thanks to the fact that one ofthe cylinders is an extended roll as an endless belt.

The document DE2125970 discloses a device including pairs of parallelrolls between which a coating film is made to be spread on a ground.This device allows a uniform spreading but it does not include finalcrumbling means for projecting the coatings to the ground.

Hence, the invention relates to a device for spreading a layer of abituminous coating on a ground to be covered, including means for movingon said ground along a longitudinal direction of advance and spreadingmeans fed with bituminous coating by feeding means and adapted to spreadduring the displacement of the device the layer of bituminous coatingover a determined width of said ground considered transversally to thedirection of advance.

According to the invention, the spreading means are adapted to makeabove the ground a rolling of the bituminous coating and a crumbling ofthe rolled bituminous coating and the falling down to the ground of thecrumbled bituminous coating.

In various embodiments of the invention, the following means, which canbe used alone or in any technically possible combination, are used:

the rolling of the bituminous coating is performed over a determinedtransverse length;

the device includes a distributing machine adapted to distribute thebituminous coating at the entry of the spreading means;

the device includes a distributing machine adapted to distribute thebituminous coating over a determined transverse length at the entry ofthe spreading means;

the spreading means are adapted to perform the projection of thecrumbled bituminous coating, so that the latter falls down to theground;

the spreading means include at least one crumbling-rolling sub-unit heldat a determined height above the ground and consisted of two roughcylinders both arranged along a same transverse direction, such that thecylinders form between them a film of bituminous coating with adetermined thickness corresponding to the determined distance betweenthe opposite generating lines of the two cylinders, the two cylindersbeing of substantially equal length, the two cylinders rotating in theopposite direction relative to each other so as to be able to carryalong between them the bituminous coating entering by an entry side ofthe crumbling-rolling sub-unit;

the rough cylinders have, on their surfaces, relief patterns forcarrying along the bituminous coating, causing, at the exit side of thecrumbling-rolling sub-unit, a crumbling of the rolled film of bituminouscoating passing between the two cylinders, as well as the falling of thecrumbled coating down to the ground,

the two rough cylinders turn, in absolute value, at the same radialspeed,

the spreading means include at least one crumbling-rolling sub-unitconsisted of an extended roll and a rough cylinder and the extended rollis formed by an end part of an endless belt extended between an upstreaminner roll and a downstream inner roll, the upstream and downstreaminner rolls being parallel to the rough cylinder, the downstream innerroll being opposite to the cylinder, the belt having a widthsubstantially equal to the length of the cylinder, a film of bituminouscoating of determined thickness being made on the upper surface of thebelt by a levelling machine arranged upstream from said belt, said filmbeing carried along towards the cylinder by the belt and the cylinderrotates, in absolute value, at a speed that is higher than the radialspeed of the belt passing over the downstream inner roll, the determineddistance between the surfaces of the rough cylinder and of the beltpassing over the downstream inner roll being lower than the determinedthickness of the film of bituminous coating made on the upper surface ofthe belt;

the levelling machine includes a transverse levelling wall whose lowerend is substantially parallel to the upper surface of the belt and whoselower end is at an adjustable determined height from the upper surfaceof the belt;

the belt section arranged between the levelling wall and the downstreaminner roll is equipped with a weighing belt system that allows tomeasure the mass of the coating vein that passes on the belt at saidweighing belt system;

the distributing machine is arranged transversally above the belt andupstream from the levelling wall, the distributing machine being adaptedto spread bituminous coating upstream from the levelling wall over adetermined width of the belt and over a height that is higher than thedetermined thickness of the film of bituminous coating to be made;

the distributing machine includes, in a cage, a worm for carrying alongthe bituminous coating over the width of the belt, the cage, closed bylateral walls, having no bottom so that the bituminous coating can bedistributed over the upper surface of the belt and being open on the topfor the feeding of bituminous coating;

the levelling wall is independent of the distributing machine cage;

the distributing machine cage is at a fixed height;

the distributing machine cage is at an adjustable height;

the height of the worm in the cage is fixed;

the height of the worm in the cage is adjustable;

the adjustment of the height of the lower end of the levelling wall isindependent of the adjustment of the height of the distributing machinecage;

the adjustment is a manual mechanical adjustment;

the manual mechanical adjustment is chosen among at least the followingmeans: adjustment by screws, bolts, shims, notches, rack, jaws;

the adjustment is ensured by a controlled position actuator;

the controlled position actuator is chosen among the electric,pneumatic, hydraulic actuators;

the levelling wall forms the downstream lateral wall of the distributingmachine cage, the distributing machine cage being located at anadjustable determined height from the upper surface of the belt;

the height of the worm in the cage is adjustable so as to be able toadjust the height of the worm with respect to the upper surface of theendless belt, whatever is the height of the cage with respect to theupper surface of the belt, in particular in the case where thedownstream lateral wall of the distributing machine cage is thelevelling wall and that the cage is adjustable in height to adjust theheight of the lower end of the levelling wall;

the device includes four crumbling-rolling sub-units each consisted of apatterned cylinder and an extended roll;

the device includes three crumbling-rolling sub-units each consisted ofa patterned cylinder and an extended roll;

the device includes two crumbling-rolling sub-units each consisted of apatterned cylinder and an extended roll;

in the case of a device including at least two crumbling-rollingsub-units each consisted of a patterned cylinder and an extended roll,the sub-units are laterally offset relative to each other so as to sumup the spreading widths of each sub-unit over a greater total width ofground, the spreading being continuous over the ground width, i.e. withno lack or with no superimposition/overlap of the spreading passes;

in the case of a device including at least two crumbling-rollingsub-units laterally offset relative to each other, the lateral offset ofthe sub-units being adjustable so as to be able to choose the totalspreading width, the spreading being continuous over the width of theground, i.e. with no lack or with no superimposition/overlap of thespreading passes;

the device includes a frame carrying two crumbling-rolling sub-unitseach consisted of a patterned cylinder and an extended roll, the twosub-units being offset, on the one hand, laterally relative to eachother, and on the other hand, in height relative to each other, the twocrumbling-rolling sub-units being mobile in translation laterallyagainst the carrying frame, so as to be able to move the two sub-unitsapart from each other or closer to each other, in overlap, along alateral direction parallel to the lane width, and to hence increase orreduce the determined width of said ground on which the bituminouscoating is spread;

the device includes one distributing machine per crumbling-rollingsub-unit, the two distributing machines of the two sub-units carryingthe bituminous coating in two opposite directions diverging over a widthof each endless belt, and the distributing machine is fed withbituminous coating through a chute in fixed position above thedistributing machine cage, and the two chutes for the twocrumbling-rolling sub-units are arranged against the median axis of thedevice superimposable to the direction of advance;

the device forms an automotive spreading machine, said spreading meansbeing arranged at the rear of said machine, or being removably installedat the rear of the automotive machine, said automotive machine includingfrom the front/upstream to the rear/downstream according to thedirection of advance: a reserve of bituminous coating, at least one linefor conveying the bituminous coating rearward and said spreading means;

the device includes at least two crumbling-rolling sub-units and onebituminous coating conveying line per sub-unit, each conveying linebeing controllable independently from the other(s) conveying lines;

the relief patterns are substantially elongated over the length of therough cylinder,

the relief patterns are essentially filiform and of a height comprisedbetween 1 mm and 15 mm.

The invention also relates to a method for spreading a layer of abituminous coating on a ground to be covered, wherein, in a first time,the bituminous coating is rolled to make a bituminous coating film ofdetermined thickness over a determined width and remote above theground, and, in a second time, said film is crumbled and the bituminouscoating of the crumbled film is made to fall down to the ground.

In a particular embodiment of said method, the bituminous coating filmof determined thickness is made over an upstream part of an extendedroll consisted of an endless belt extended between an upstream innerroll and a downstream inner roll, and a rough cylinder including reliefpatterns is implemented opposite the downstream inner roll to crumblethe film made on the endless belt.

In certain particular embodiments of the method, a bituminous coating isused, which is chosen among: a hot coating having a fabricationtemperature higher than 150° C., a warm coating having a fabricationtemperature higher than 100° C. and lower than 150° C., a half-warmcoating having a fabrication temperature between 85° C. and 100° C., ahalf-cold or cold coating having a fabrication temperature lower than85° C.

In certain particular embodiments of the method, a bituminous coating isused, whose values d and D of the d/D ratio are chosen among: a value of0-2-4 or 6.3 mm for d and a value of 4-6.3-10-14-20 mm for D.

The present invention will now be exemplified, without being limitedthereby, by the following description in relation with the followingfigures, in which:

FIG. 1 shows a simplified block diagram of bituminous coating spreadingmeans in the embodiment with an extended roll consisted of an endlessbelt extended between an upstream inner roll and a downstream innerroll,

FIG. 2 shows an oblique and perspective front view of a finishingmachine equipped on the rear with two bituminous coating spreading meansaccording to the embodiment with an extended roll,

FIG. 3 shows an oblique and perspective rear view of a finishing machineof FIG. 2 equipped with its two bituminous coating spreading means withan extended roll,

FIG. 4 shows a rear and perspective lateral view of a first side of theequipped finishing machine of FIG. 2,

FIG. 5 shows a rear and perspective lateral view of a second side of theequipped finishing machine of FIG. 2,

FIG. 6 shows a closer lateral view, centred on the worm-baseddistributing machine of the first of the bituminous coating spreadingmeans located on the first lateral side of the equipped finishingmachine of FIG. 2,

FIG. 7 shows a closer lateral view, centred on downstream inner rolldriving the endless belt and on the corresponding patterned cylinder ofthe bituminous coating spreading means located on the second lateralside of the equipped finishing machine of FIG. 2,

FIG. 8 shows a closed rear view of the equipped finishing machine ofFIG. 2,

FIG. 9 shows a perspective rear lateral view of the equipped finishingmachine of FIG. 2, in operation, with projection and falling down ofcrumbled bituminous coating to the ground,

FIG. 10 shows a schematic cross-section of spreading means with tworough cylinders, and

FIG. 11 schematically shows a trailer towed by bituminous coatingspreading means according to the invention and which includes inparticular three wheels that are cylinders with smooth wheel rims andmeans for storing water and a bonding/sealing emulsion, as well as meansallowing to use these products.

In its general principle, the invention is characterized in that thespreading of the bituminous coating is performed by rolling means thatcondition the coating into a film of controlled thickness and over acontrolled width before being splintered/crumbled and to fall down tothe ground by being preferably projected to the latter. The making ofthe film is qualified as rolling and the film is obtained by passing thebituminous coating between two elements that are mobile relative to eachother, in particular two rotating cylinders or between a fixed elementrelative to a mobile element, in particular a levelling wall withrespect to an endless belt of an extended cylinder.

In the case where two cylinders are used, the film of bituminous coatingof determined thickness is made between the two cylinders preferablyrotating at the same absolute radial speed so as to facilitate thedosage. If, preferably, the two cylinders turn in opposite directions,the case is contemplated in which they would turn in the same direction,in particular in the case where one of the cylinders turn faster thanthe other to project the bituminous coating to the ground. It may hencebe chosen to have different absolute radial speeds for the two cylindersbut, in certain conditions, this could complicate the theoreticalestimation, on the paper, of the quantity of material of the film, dueto effects that can be nonlinear. In such cases, measurements on amachine in activity will allow, if desired, to obtain dosage curves as afunction of the adjustments of the machine. Indeed, it has been observedin certain conditions, during tests, an absence of linearity of thedosage with the radial speed of the roll(s) and also with the spacingbetween the rolls.

In case of use of an extended cylinder, the moving of an endless belt iscombined with successive functions of feeding with bituminous coating,transverse distribution of the bituminous coating on the endless belt,creation on the endless belt of a film of bituminous coating having adetermined thickness, crumbling of the film and spreading by fallingdown, and preferably projection, of the crumbled film to the ground.

The ground on which the layer is spread is preferably a ground preparedto receive said layer of bituminous coating. A bonding and/or sealinglayer may be applied on the ground before spreading of the bituminouscoating or simultaneously during the spreading.

In the present description, the words “front” and “rear” are definedwith respect to the direction of advance on the ground of the spreadingmeans, the spreading means moving forward. The words “upstream” and“downstream” are defined with respect to the direction of circulation ofthe bituminous coating in the spreading means, the spreading beingperformed downstream to form on the ground a layer of bituminouscoating, the bituminous coating arriving into the spreading means fromthe upstream.

In the spreading machine that will be described in more detail, on theone hand, the rear and the downstream correspond to each other becausethe spreading is made on the rear, and on the other hand, the upstreamis oriented forward. Moreover, the spreading means are arranged on therear of the machine. Other arrangements may however be contemplated,with for example a spreading machine in which the downstream of the unitis oriented toward the front of the machine and/or the spreading unit isarranged on the front, wherein the machine can moreover be a rollingmachine.

Thanks to the invention, the dosage of the bituminous coating is appliedin a uniform and continuous way whatever the deformations of the ground,provided that it is possible for building machines, and in particularthe spreading machine implementing the invention, to circulate thereon.The invention allows a controlled dosage of the spreading of thebituminous coating over a range of 6 kg/m² to at least 50 kg/m².

Moreover, given that the invention can be applied to all the hotcoatings, the warm coatings, the half-warm coatings, the half-coldcoatings, the cold coatings of the emulsion gravel type, the cold opencoatings, or the cold dense coatings, it is possible to adapt theformulation of the bituminous coating to the particularities of thespreading working place. The adaptation may be done as a function of thethickness of the layer of bituminous coating it is desired to beobtained, as a function of the characteristics of the support and inparticular as a function of the level of the deflections and/or as afunction the aggressiveness of the traffic.

For example, for applications as a thin layer which correspond todosages comprised between 6 kg/m² and less than 30 kg/m², it may be useda continuous or discontinuous formulation with a high richness module:dosage of binder higher than 5.4% and dosage of the elements of sizelower than 63 μm higher than 6%, preferably, and with the use of anasphalt of a grade chosen among 50/70, 70/100, 160/220, 250/330,330/430, 500/650, 650/900, or of modified asphalts. The modifiedasphalts are preferably used for roads having a high circulation orroads that, due to their geometric configuration, in particular sinuousand/or as a ramp . . . , generate high constraints.

For depositions in thicker layers, in a range of 30 to 60 kg/m², thecoating may be formulated in accordance to the texts or standards inforce. For the gravel emulsions, according to the standard NF 98-121.For the BBUM (Ultra-Thin Bituminous Concrete), with a mean dosage of 30kg/m², in accordance to the standard NF EN 13109-9. For the BBTM (VeryThin Bituminous Concrete) with a mean dosage of 60 kg/m², in accordingto the standard NF EN 13 108-2. For the BBM (Thin Bituminous Concrete)of mean dosage 90 kg/m², i.e. 4 cm of nominal thickness, in accordanceto the standard NF EN 13 108-1. For the BBF, in accordance to thestandard NF EN 98-139. For the BBDr (Draining Bituminous Concrete).

The invention may be applied to bituminous coating whose (D) is 4 mm,6.3 mm, 10 mm or 14 mm, and the (d) of the bituminous coating is equalto 0 mm, 2 mm, 4 m or 6.3 mm. It is reminded that the grain-size class,noted d/D with d<D, denotes an interval of particle sizes in terms oflower size (d) and upper size (D) of screen, expressed in mm. Theconventional means for producing bituminous coating may be used withinthe framework of the invention, in particular hot coating plant or coldcoating plant.

In the following of the description, the embodiment with an endlessbelt, i.e. with implementation of spreading means including a patternedcylinder and an extended roll, will be more particularly detailed, giventhat the film of determined thickness made in this device has a lifeduration and an extension higher than the embodiment with acrumbling-rolling sub-unit having two patterned cylinders, which makethe explanation easier. Indeed, in the embodiment with a sub-unit havingtwo patterned cylinders, the film of bituminous coating made between thepatterned cylinders is almost immediately crumbled due to the fact thatthe zones of creation of the film and of crumbling are very close theeach other. The implementation of an endless belt comes to use acylinder that is in an extended form and it is hence possible tofurthermore separate the zone of creation of the film of bituminouscoating from that of the crumbling of said film.

In a variant equivalent to the first embodiment with a sub-unit havingtwo patterned cylinders, two extended cylinders, consisted of twoopposite endless belts with relief patterns, rotating in the samedirection for the opposite belt parts, preferably with the same radialspeed in absolute value, may be implemented. In such a case, it isunderstood that this allows to separate the zone of creation of the film(upstream, entry side of the unit with two patterned extended cylinders)from the crumbling area (downstream, exit side of the unit with twopatterned extended cylinders). The adjustable spacing between the twoopposite endless belts allows to adjust the thickness of the film ofbituminous coating and hence the dosage, hence the quantity, ofbituminous coating spread on the ground. The fact to constrain the filmof bituminous coating between two endless belts of two patternedextended cylinders allows a vertical arrangement, inclined orhorizontal, of the two patterned endless belts.

The endless belt and the combined operational means are integral andcarried by an automotive tractor machine that ensures a function ofmotricity of controlled speed and brings the energies and fluidsrequired for the good operation of the spreading device. This machine isgenerally a finishing machine or a finishing tractor that ensures thedisplacement as well as the bituminous coating, energy and fluid feedingfunctions, and the spreading device is then installed at the place ofthe finishing table. In the first case, a specific machine is made and,in the second case, a conventional machine is used, the device beingadded on the tractor in replacement of the conventional spreading tool.In still another variant, the device of the invention is a trailer thatcan be towed by an automotive machine, for example a bituminous coatingdelivery truck, a fast coupling means being implemented between them.

In the block diagram of FIG. 1 showing a sub-unit 1 with a cylinder 12provided with relief patterns 13 and an extended roll consisted of anendless belt 8 between an upstream inner roll 10 and an downstream innerroll 9, the bulk bituminous coating arrives on the upstream/entry sideof the unit, which has been shown by a wide curved arrow 11 on the leftof FIG. 1 and which corresponds to a bituminous coating feedingfunction. The bituminous coating arriving on the endless belt on theupstream side is spread transversally/laterally over the width of thebelt 8 by a distributing machine 7 ensuring the function of transversedistribution of the bituminous coating on the belt 8. The upper face ofthe belt 8 which receives the bituminous coating moves from the upstreamto the downstream. In this functional scheme, the distributing machine 7also ensures a function of levelling machine so as to form a film 6 ofbituminous coating of determined thickness on the belt 8. In FIG. 1,certain areas of the film 6 has been omitted to allow to seen the belt 8that supports the film 6 and, indeed, the film 6 of bituminous coatingled downstream by the belt 8 is continuous at the exit of thedistributing machine 7 having a levelling machine function. This film 6is crumbled on the downstream/exit side of the unit by a cylinder 12having relief patterns 13 arranged opposite the downstream inner roll 9.In FIG. 1, the spacing between the cylinder 12 with patterns 13 and thebelt 8 carried by the downstream inner roll 9 has been exaggerated tobetter schematize the crumbled bituminous coating 5 projected down tothe ground 2. In practice, the spacing between both is lower than thethickness e of the film 6 so that the relief patterns 13 of the cylindercan effectively carry along and crumble the bituminous coating of thefilm 6. These relief patterns 13 of the cylinder 12 are preferablysubstantially elongated in the direction of the cylinder length: blades,chevrons . . . . In a variant, these are “bristles” or picks of thebrush-type but they have then an efficient driving surface that issmaller than the patterns elongated along the cylinder length.

The crumbled bituminous coating projected down to the ground 2 thenforms thereon a layer 4 of bituminous coating on which a rolling roll issubsequently passed. In FIG. 1 is schematized the previous applicationof a sealing and binding layer 3 before the spreading of the crumbledbituminous coating 5. The unit that is above the ground 2 moves in thedirection indicated by the arrow 32. It is hence understood that it iscreated with the film of bituminous coating carried and transported bythe belt 8, the equivalent of the layer 4 that is formed on the ground,the dosage on the ground however depending on the speed of advance ofthe unit on the ground as will be described in more detail latter.

The belt 8 is consisted of a rubber belt that resists to the hightemperatures, at least up to 180° C., or any other means that allows tosupport the coating and to transport it with a linear speed comprisedbetween 2 meters per minute and 20 meters per minute. The belt,substantially horizontal, is supported by two inner rolls, an upstreaminner roll 10 on the side of arrival of the bituminous coating and adownstream inner roll 9 on the side of crumbling of the bituminouscoating film. One of the inner rolls of the endless belt is a drivingroll to ensure the rotation of said belt. Preferably, it is thedownstream inner roll 9 that is a driving roll to maintain tensioned thebelt carrying the coating film. The motor is preferably a hydraulicmotor.

The spacing between the inner rolls 10, 9 gives an efficient length ofthe endless belt 8 of at least 1 m, the efficient length corresponds tothe upper surface of the endless belt 8 on which the bituminous coatingfilm 6 is made and transported. Furthermore, between the inner rolls 10,9, at least the upper part of the endless belt slides over a rigid plateto prevent the latter to be deformed under the load of the bituminouscoating film and hence to keep a film of constant thickness.

The bituminous coating feeding function 11 for the distributing machine7 arranged above an endless belt 8 is ensured by a conveyor or any otherdevice that allows to ensure a bituminous coating flow rate comprisedbetween 10 tons per hour and 100 tons per hour.

We will now describe, starting by FIG. 2, the implementation of thebituminous coating spreading device on a finishing tractor 14 inreplacement of a conventional finishing table. The device is installedon a removable module 33 that may be connected to the rear of thefinishing tractor 14 in replacement of the finishing table. The devicesplit into two sub-units each consisted of a patterned cylinder 12 andan extended roll of the endless belt 8 type.

In FIG. 2, the finishing tractor 14 includes, in front, a bituminouscoating buffer tank 35 that can be laterally open to come on the rear ofthe truck for being fed with bituminous coating. Protective members 29in the front of the tractor allow to push the bituminous coating truckas the finishing tractor moves forward on the ground thanks to tracks28. A motor and piloting unit is arranged on the rear of the buffer tank35. A conveyor that is not visible but signaled by the reference 30 withdashed-line arrows, takes bituminous coating from the bottom of thebuffer tank 35 to send it to the rear of the finishing tractor bypassing between the tracks 28 and under the motor and piloting unit.This conveyor 30 is herein double, with two parallel lanes able to becontrolled independently from each other as a function of the needs inbituminous coating for each sub-unit 1 a, 1 b having a cylinder 12 withpatterns 13 and extended roll 8, 9, 10.

In FIG. 3, we can see more precisely the removable module 33 with itstwo sub-units 1 a and 1 b having cylinders 12 with relief patterns 13and extended rolls each consisted by an endless belt 8 between anupstream inner roll 10 and a downstream inner roll 9. The two sub-units1 a, 1 b are offset both laterally and vertically. The lateral offsetbetween the two sub-units 1 a, 1 b is adjustable so as to be able toperform a more or less wide layer of bituminous coating on the ground.The two sub-units 1 a, 1 b may hence more or less overlap, hence thenecessity of the height offset so that one of them 1 b can pass underthe other 1 a.

The removable module 33 includes a rigid support frame 16 fixed to thefinishing tractor and whose inclination and/or height with respect tothe finishing tractor may be adjusted thanks to controlled jacks. Abridge is fixed on the upper part of the support frame 16 so as to allowthe staff to accede to the piloting station and to observe the operationof the two sub-units, or even to adjust certain members accessible fromthe bridge.

The two sub-units 1 a, 1 b are laterally slidingly carried by thesupport frame 16 through rolling members 17 towards the rear/downstreamof the sub-units and 17′ towards the front/upstream of the sub-units. Itis to be noted that the unit 1 a that is the highest also slidinglysupport towards the rear/downstream the unit 1 b that is the lowest. Itcan be seen more precisely in FIG. 7 one of the embodiments of therolling members 17 for the sub-unit 1 b.

The cylinder 12 with patterns 13 is driven into rotation by a hydraulicmotor 26 and the downstream inner roll 9 by a hydraulic motor 25 that isbest seen for the unit 1 a because theses motors are on the side of theobserver. A belt doctor 34 is arranged downward the downstream innerroll 9 so as to scrape the upper/outer surface of the belt 8 and to makefall down to the ground the bituminous coating that could have stayedstuck on the belt after the latter has passed under the cylinder 12 withpatterns 13.

On the side of the sub-unit 1 b that is the most visible in FIG. 3, itcan be seen towards the upstream of the endless belt 8, the levellingwall 22 of the levelling machine that is at the rear/downstream of thecage 15 of the distributing machine 7.

The transverse distribution function of the distributing machine isensured by a worm, visible in FIGS. 5 and 6 for each sub-unit 1 a, 1 bpositioned in a cage 15 open at the upper part to receive the coatingcoming from a ramp 21 and from the conveyor 30 and open in the lowerpart to transversally distribute the coating over the belt 8. In orderto ensure the regularity of the transverse distribution of thebituminous coating by the worm on the endless belt, this transversedistribution of the coating is performed in the cage 15 over a width ofthe belt by making a vein whose thickness is preferably at least higherthan four times the (D) of the coating. For example, with a coating0/10, the vein under the worm must have preferably a minimum thicknessof 40 mm.

In practice, the bituminous coating, characterized by its d/D, may bechosen with a value of 0-2-4 or 6.3 mm for the (d) and a value of4-6.3-10-14-20 mm for the (D). Likewise, the bituminous coating may bechosen among a hot coating having a fabrication temperature higher than150° C., a warm coating having a fabrication temperature higher than100° C. and lower than 150° C., a half-warm coating having a fabricationtemperature between 85° C. and 100° C., a half-cold or cold dense havinga fabrication temperature lower than 85° C.

As can be seen in FIG. 4 for the unit 1 a, a spraying ramp 19 of asealing and/or bonding product is arranged in the upstream/front of thesub-units. This spraying ramp is fed with a bonding/sealing emulsion bydevices that will be described in relation with the trailer of FIG. 11and that comprise in particular an emulsion tank and an emulsion pump.These spraying ramps follow the lateral displacement of the sub-unitsduring the adjustment of the spreading width. Preferably, during theimplementation of the device, it is first spread on the ground, byspraying with the spraying ramp, a bounding layer in front of thefalling down and projection on the ground of the crumbled bituminouscoating.

It can be noted the presence of a level sensor 18 on the lateral end ofthe cage 15 of the worm-based distributing machine 7 of the unit 1 a.This level sensor 18 is arranged on the lateral side of the cage 15,i.e. opposite the place of the cage 15 where arrives the bituminouscoating by the feeding function 11, the upper end of the feeding ramp 21of which can be seen. The worm rotates so as to send and distribute thebituminous coating into a vein towards the lateral end of the cage 15.This sensor 18 allows to cut the bituminous coating feeding 11 whenthere is enough bituminous coating in the case and that may have reachthe lateral side of the cage. A possible overflow of the bituminouscoating out of the cage is hence avoided, while ensuring a correctdistribution of the coating over the surface of the endless belt 8 andin order to obtain a uniform film.

The two feeding ramps 21 of the two sub-units receive the bituminouscoating arriving by the double conveyor 30 arranged between the tracks28 of the tractor 14. These two feeding ramps 21 allow to move thebituminous coating up above the two cages 15 of the two sub-units 1 a, 1b. The two feeding ramps are in fixed positions and are arranged oneither side of the median axis of the tractor and of the module 33,substantially against each other. It is hence understood that thebituminous coating will fall down into the cage at a place that willdepend on the lateral position of the unit 1 a, 1 b. When each sub-unit1 a, 1 b is fully pushed outward to obtain a maximal layer width, theplace where the bituminous coating falls down into the cage is thecentral end, i.e. towards the median axis, of the cage 15 and the filmis hence made over the whole width of the endless belt 8.

On the other hand, when the sub-units are close to each other andoverlap each other for making a narrower layer, the place where thebituminous coating falls into the cage is an intermediate positionbetween the two lateral and central ends of the cage 15. It results fromthe fact that the worm distributes the coating toward the lateral sidethat the film will be made only over a reduced width of the endless beltand on the lateral side of the latter. Thanks to that, there is nooverlap of spreading in the central area of the layer and hence nodouble thickness of the layer in its central area when it has beenchosen a layer width that is lower than the maximum width of spreadingby moving closer and overlapping of the two sub-units 1 a, 1 b.

The bituminous coating feeding of the distributing machine is preferablycontrolled by its own automatism that does so that the vein ofbituminous coating in the cage 15 will have the required minimumthickness for a correct distribution, while avoiding an overflow of thebituminous coating out of the cage. At least one sensor 18 is henceimplemented within the cage to stop the feeding of the latter when thelevel of bituminous coating rises too high in the cage, with a risk ofoverflow. The bituminous coating feeding of the cage is resumed when thelevel of coating goes down in the cage and risks to pass under therequired minimum thickness. It is also implemented a level sensor at theexit of each feeding ramp 21, in the corresponding chute 31. Thanks tosuch an automatism, the device can operate correctly even if theadjustments thereof are modified to modify the dosage of the layerobtained on the ground.

FIG. 5 allows to view the worm 20 in the cage 15 of the distributingmachine 7 of the unit 1 b. The same members than those described in FIG.4 for the unit 1 a, and in particular the level sensor 18, are found. Itcan be noted the presence of a chute 31 just under the end of thefeeding ramp 21 and above the opening of the top of the cage 15, thechute being fixed as the feeding ramp 21 (it is reminded that the cage15 can move under the chute). This chute 31 forms a funnel intended toguide into the cage 15 the bituminous coating that falls from thefeeding ramp 21.

In FIG. 6 can be seen the worm 20 in the cage 15 of the distributingmachine 7 of the unit 1 a.

The function of creating, on the belt, a bituminous coating film havinga determined thickness comprised between 20 mm and 100 mm to within moreor less 2 mm is ensured by a levelling wall 22 forming the guillotine ofa levelling machine. The thickness of the bituminous coating film ispreferably at least equal to four times the (D) of the bituminouscoating. For example, for a coating 0/10, the thickness of the filmunder the guillotine will be preferably at least equal to 40 mm. Theposition in height of the levelling wall 22 forming the guillotine ofthe levelling machine with respect to the upper surface of the belt isadjustable so as to be able to choose the thickness of the bituminouscoating film and hence to adjust the dosage of bituminous coating spreadon the ground.

The function of creation of the bituminous coating film may beassociated with the function of transverse distribution. It ispreferable that the two conditions relating the thicknesses of the veinin the cage and of the film on the belt are respected, i.e. a veinthickness at least equal to four times the (D) of the bituminouscoating, and a film thickness at least equal to four times the (D) ofthe bituminous coating, modifications of these thicknesses having to bemade in a correlated manner.

The bituminous coating film that is transported by the endless belt isthen dislocated by being crumbled by a cylinder 12 with patterns 13,then spread on the ground by falling down, preferably the patternedcylinder rotating at a rotational speed such that the crumbledbituminous coating is projected to the ground.

In FIG. 7 are seen more precisely the relief filiform patterns 13 ofextension substantially longitudinal along the cylinder 12. They resultfrom the welding on the cylinder 12 of an expanded metal grid withdiamond patterns and of a few millimetres thick.

The relief patterns are filiform and are essentially elongated along thelength of the cylinder and form bituminous coating driving patterns.Typically, the relief pattern is similar to a substantially regularrepetition of square edge or diamond edge shapes. Other elongated shapesare possible, for example saw-teeth, triangle, chevrons, zigzag . . .but they all have a substantially longitudinal extension, over thelength of the cylinder, so that the driving effect of the bituminouscoating is efficient. These relief patterns may be integrated or addedon the surface of the cylinder.

If, preferably, the relief patterns at the surface of the cylinder arefiliform, it may be implemented as an alternative a hedgehog cylinderincluding points and/or blades for the crumbling of the film and theprojection the bituminous coating towards the ground. It is to be notedthat the projection to the ground of the bituminous coating resultingfrom the crumbling of the film may be more or less important accordingto the needs, the crumbled bituminous coating falling naturally down tothe ground due to the fact that it is released from the endless belt,the latter rolling downward around the downstream inner roll and goingback towards the upstream at the bottom of the device. It is howeverpreferable that the patterned cylinder rotates fast enough so that thecrumbled bituminous coating can be detached efficiently from saidcylinder under the effect of the centrifugal force. With a too slowrotational speed of the patterned cylinder there is a risk of formationof too voluminous packets of bituminous coating. Hence, it is preferredthat the patterned cylinder rotates rapidly to project the crumbledbituminous coating to the ground. In practice, the radial speed of thepatterned cylinder is higher than the radial speed of the endless belt.

The cylinder 12 with patterns 13 has an efficient length substantiallyidentical to the efficient width of the conveyor belt 8, and it isplaced at the downstream end of the endless belt 8, opposite thedownstream inner roll 9. The diameter of the cylinder 12 with patterns13 is of at least 150 mm.

In the case of a hedgehog cylinder, the points of the hedgehog arespaced apart by about 10 mm and have a length of 50 mm for a coating ofgrain size 0/10. More generally, it may be provided different patternedcylinders, or different patterns if the patterns are removable, adaptedto the grain size of the coating to be projected. In the case where therelief patterns, filiform or hedgehog, have a great height able to do sothat they come into contact with the belt, it is provided that theserelief patterns have a certain flexibility to retract upon contact withthe belt.

The distance between the patterned cylinder and the belt passing on thedownstream inner roll that is opposite said patterned cylinder isadjustable by adjustment means 23 visible in FIG. 7. The spacing betweenthe upstream and downstream inner rolls, and hence the tension of theendless belt, is adjustable thanks to adjustment means 24 acting moreparticularly on the position of the downstream inner roll 9. It can benoted that the adjustment of the position of the downstream inner roll 9automatically causes the displacement of the cylinder 12 with patterns13 and of the belt doctor 34 due to the fact that these latter aremounted on a common adjustment plate. These adjustment means 23 and 24are herein manually operable but in other embodiments, they are operatedby controlled position actuators. It is understood that theseadjustments are possible at the two ends of the cylinder 12 withpatterns 13 and of the extended roll 8, 9, 10, so as to keep aparallelism between both and so that the belt between its upstream anddownstream inner rolls.

A motor 26, preferably hydraulic, ensures the rotation of the patternedcylinder at a speed of 200 to 400 rpm. These values are given by way ofindication as an order of magnitude for a better understanding.

A belt doctor 34 is arranged downward the downstream inner roll to scrapthe surface of the endless belt in the case where bituminous coatingwould remain stuck on the belt and hence make it fall down to the groundwhere it will join the remaining of the bituminous coating that had beencrumbled and detached from the belt by the patterned cylinder.

In FIG. 8, we can perfectly see the very partial overlap of the twosub-units 1 a, 1 b du to the fact that they are positioned to make alayer whose width corresponds to the maximal possible width due to thefact that the spacing between the two sub-units is maximum. It isunderstood that this very partial overlap is linked to the fact that theuseful width of the belt, hence of the film, is a little lower than thewidth of the unit and that, to avoid a lack of bituminous coatingtowards the centre of the layer, the useful widths of the belts mustjoin the median axis of the tractor and of spreading. When it is desiredto make a layer having a width equal to or lower than the useful widthof the belt, only one of the two sub-units is operated.

It is understood that the speeds of the different elements of the deviceare adapted between each other so that there is no cutting of supply orclogging along the path of the bituminous coating in the device. In thecase of a normal operation with no breaking or clogging, it is possibleto calculate the dosage of the bituminous coating that is spread on theground with the following formula:

Dosage(kg/m²)=1000*MVA*Ev*Vr/Va

where

MVA (M·g/m²) is the bulk density of the film on the endless belt,

Ev (m) is the thickness of the film on the endless belt,

Vr (m/min) is the speed of advance or rotation of the belt,

Va (m/min) is the speed of advance of the device on the ground.

The bulk density of the film on the endless belt, MVA, is determined foreach formula of bituminous coating. The thickness of the film, Ev, isadjustable and it is preferably chosen a thickness equal to four times(D), (D) being the greatest dimension of the gravels that compose theformula of the bituminous coating. The speeds of advance or rotation ofthe endless belt and the speed of advance of the device with respect tothe ground are synchronized and dependent on each other so as to obtainthe desired dosage for the layer on the ground.

In a variant, a weighing means is installed under the belt sectionarranged between the levelling wall and downstream inner roll so as tomeasure the mass of the coating vein that passes on the belt at saidweighing means, this means being a weighing belt system that can forexample be consisted of a weighing roll extended under the belt. It isthus possible to continuously measure the weight of the coating movingon the belt. This weighing means may be used in combination with thedosage calculation explained hereinabove or to be used alone to adjustthe dosing. It hence exists several means to control the speed ofadvance of the device on the ground and the desired dosage.

It is understood that it is possible to act on one or several parametersto adjust the dosage of the bituminous coating of the layer on theground, which allows a very high flexibility of operation.

A regulating automaton is implemented to command and control thedifferent elements of the device. The operation of the spreading devicemay be adjusted in various ways. Generally, it is chosen a dosage inkg/m² to be obtained for the layer on the ground and the automatonadjusts the parameters of speed of the advance of the device on theground, of speed of rotation of the belt, of thickness of the film forthat purpose. In some cases, one of the parameters may be constrained:for example the speed of advance of the device is moreover imposed by anoperator and the automaton hence adjusts the two other parameters. It isto be noted that the automaton may include tables or formulas ofcalculation giving possible areas of values of parameters as a functionof the dosages. It is then possible to implement securities informingthe operator about an impossibility to reach the desired dosage. Forexample, if the operator imposes a too high speed of advance of thedevice for a given formulation and a desired dosage, the automaton willindicate an impossibility and will possibly be able to indicate acompliant lower speed of advance of the device. The automaton mayfurther determine as a function of the desired dosage, an optimum speedof advance of the device in terms of consumption and/or of roadwork timeor any other criterion of optimization, as for example the speed orperiod of rotation of the semi-trailers supplying the bituminous coatingto the machine having the spreading device.

Likewise, the automate may take into account, thanks to sensors, ofcertain deformations of the ground on which the layer must be performed.Hence, the dosage to be applied at the plane coordinates x-y, may bemade proportional to the deformation in z of the pavement. The values inz as a function of the couple x-y may be predefined and used for themanagement of the regulation automaton or be measured in real time. Insuch a mode, the operator may possibly define maximum and minimum limitsof the dosage.

In FIG. 9, it can be seen that the finishing tractor in action,spreading a layer 4 of bituminous coating. It can be noted that the unit1 a is higher and more on the rear than the unit 1 b, this rear offsetof the top unit 1 a is due to the fact that its feeding ramp 21 islonger and that it has the same inclination than that, shorter, of thelow unit 1 b. A film of bituminous coating is made on the whole usefulwidth of each belt 8 and this film is crumbled by the correspondingpatterned cylinder 12 to form crumbled bituminous coating 5 that fallsdown to the ground to form the layer 4. It can be noted that theobtained layer 4 has a relatively reduced thickness, which would beuneasy to obtain with a conventional finishing.

Spreading means with two rough cylinders are schematized in FIG. 10 witha lateral sectional view of a crumbling-rolling sub-unit 100. In thiscross-section, a hopper 102 includes on the upstream side ofintroduction of the bituminous coating, a spreading machine 7, and onthe downstream side of exit of the crumbled rolled bituminous coating 5,two rough cylinders 112 that ensure the rolling of the spread coatingand the crumbling of the bituminous coating film resulting from therolling. The crumbling is performed almost immediately after the rollingin this embodiment. The feeding function 11 has been shown by anenlarged arrow but, as a variant, the hopper 102 instead of being asimple hopper for introducing the bituminous coating 101 coming from astoring means located upstream, may also be a means for storing thebituminous coating. In the latter case, it may be interesting that thestoring means of the hopper 102 is a little offset with respect to thevertical of the exit of the crumbled rolled bituminous coating 5 so thatthe variable weight of the column of stored bituminous coating whoseheight may vary has a little influence on the dosage of the bituminouscoating at the exit, this offset may correspond to a bent or a fallinclined towards the spreading machine 7 and the two rough cylinders112.

FIG. 11 schematically shows a trailer on rolls 114 attached to aspreading device according to the invention, for example that with acrumbling-rolling sub-unit 100 equipped with two rough cylinders asdescribed hereinabove. This trailer, in addition to its ability to storea bonding/sealing emulsion, allows, after the spreading of thebituminous coating layer on the ground, the rolling of said layer. Thetrailer 114 includes two rolling rolls 115 allowing the displacement ofthe machine on the layer 4. The trailer 114 includes a divided tank 116of 6 m³ with a first part for a bounding/sealing emulsion and a secondpart for the water intended for the watering of the rolling rolls 114.These rolling rolls 115 are shown as being three, but it is understoodthat this number and/or the rolling structure of the machine may beadapted as a function of the needs, as well as the length of eachrolling roll that is herein of 1.50 m and with smooth wheel rims. Thetrailer 114 also includes a platform with a pump for the bonding/sealingemulsion, a pump for the watering of the rolling rolls and an aircompressor for forming jets from the bonding/sealing emulsion ramp 19.The trailer may also include a generating plant.

It has been schematically shown in the front of the trailer 114,according to the direction of advance 32 of the unit, a ramp 19 forspraying a layer 3 of bonding emulsion to the ground 2 and a spreadingsub-unit. The compressed bonding/sealing emulsion and air aretransmitted to the ramp 19 through flexible pipes schematically shown bydashed lines in FIG. 11. At the rear of the ramp 19 is located thecrumbling-rolling sub-unit 100 equipped with two rough cylinders thatallows to make the crumbled bituminous coating 5 fall down to theground, possibly by projecting in to the ground, and to make the layer 4of bituminous coating on the ground 2. The rolling rolls of the traileract more on the rear to roll the bituminous coating layer 4 that hasbeen made. Linking means 117 allow to link the trailer 114 to thespreading machine, which includes the spreading sub-unit(s).

1-18. (canceled)
 19. A device for spreading a layer (4) of a bituminouscoating on a ground (2) to be covered, including means for moving onsaid ground along a longitudinal direction of advance (32) and aspreading system fed with bituminous coating by feeding means andadapted to spread during the displacement of the device the layer ofbituminous coating over a determined width of said ground consideredtransversally to the direction of advance, the spreading system beingadapted to make above the ground a rolling of the bituminous coating anda crumbling of the rolled bituminous coating and the falling down to theground of the crumbled bituminous coating, wherein the spreading systemincludes at least one crumbling-rolling sub-unit consisted of anextended roll and a rough cylinder, and wherein the extended roll isformed by an end part of an endless belt (8) extended between anupstream inner roll (10) and a downstream inner roll (9), the upstreamand downstream inner rolls being parallel to the rough cylinder (12),the downstream inner roll (9) being opposite the cylinder (12), the belt(8) having a width substantially equal to the length of the cylinder, abituminous coating film (6) of determined thickness (e) being made onthe upper surface of the belt (8), said film being carried along towardsthe cylinder by said belt, said film being carried along toward thecylinder by said belt, the determined distance between the surfaces ofthe rough cylinder and of the belt passing over the downstream innerroll being lower than the determined thickness (e) of the bituminouscoating film (6) made on the upper surface of the belt (8).
 20. Thedevice according to claim 19, wherein the spreading system is adapted toperform the projection, for its falling down to the ground, of thecrumbled bituminous coating.
 21. The device according to claim 20,wherein the cylinder rotates, in absolute value, at a speed higher thanthe radial speed of the belt (8) passing on the downstream inner roll(9).
 22. The device according to claim 19, further comprising adistributing machine adapted to distribute bituminous coating at theentry of the spreading system.
 23. The device according to claim 19,wherein the bituminous coating film (6) of determined thickness (e) ismade on the upper surface of the belt (8) by a levelling machinearranged upstream from said belt.
 24. The device according to claim 23,wherein the levelling machine includes a transverse levelling wall (22)whose lower end is substantially parallel to the upper surface of thebelt (8) and whose levelling end is at an adjustable determined heightfrom the upper surface of the belt.
 25. The device according to claim24, wherein the belt section (8) arranged between the levelling wall(22) and the downstream inner roll (9) is equipped with a weighing beltsystem that allows to measure the mass of the coating vein that passeson the belt at said weighing belt system.
 26. The device according toclaim 24, wherein the distributing machine (7) is arranged transversallyabove the belt (8) and upstream from the levelling wall (22), thedistributing machine (7) being adapted to distribute bituminous coatingupstream from the levelling wall over a determined width of the belt andover a height that is higher than the determined thickness (e) of thebituminous coating film (6) to be made.
 27. The device according toclaim 22, wherein the distributing machine (7) includes, in a cage (15),a worm (20) for carrying along the bituminous coating over the width ofthe belt (8), the cage, closed by lateral walls, having no bottom sothat the bituminous coating can be distributed over the upper surface ofthe belt and being open on the top for the feeding (11) of bituminouscoating.
 28. The device according to claim 27, wherein the levellingwall (22) constitutes the downstream lateral wall of the cage (15) ofthe distributing machine (7), the distributing machine cage beinglocated at an adjustable determined height from the upper surface of thebelt.
 29. The device according to claim 19, further comprising a frame(16) carrying two crumbling-rolling sub-units (1 a, 1 b) each consistedof a rough cylinder (12) and an extended roll (8, 9, 10), the twosub-units (1 a, 1 b) being offset, on the one hand, laterally relativeto each other, and on the other hand, in height relative to each other,the two crumbling-rolling sub-units being mobile in translationlaterally against the carrying frame, so as to be able to move the twosub-units apart from each other or closer to each other, in overlap,along a lateral direction parallel to the lane width, and hence toincrease or reduce the determined width of said ground on which thebituminous coating is spread.
 30. The device according to claim 29,further comprising one distributing machine (7) per crumbling-rollingsub-unit, the two distributing machines of the two sub-units carryingthe bituminous coating in two opposite directions diverging over a widthof each endless belt, wherein the distributing machine is fed withbituminous coating through a chute (31) in fixed position above the cage(15) of the distributing machine (7), and wherein the two chutes (31)for the two crumbling-rolling sub-units (1 a, 1 b) are arranged againstthe median axis of the device superimposable to the direction of advance(32).
 31. The device according to claim 19, wherein the device forms anautomotive spreading machine, said spreading system being arranged atthe rear of said machine, or being removably installed at the rear of anautomotive machine (14), said automotive machine including from thefront/upstream to the rear/downstream according to the direction ofadvance: a reserve (35) of bituminous coating, at least one line (30)for conveying the bituminous coating rearward and said spreading system.32. The device according to claim 19, wherein relief patterns (13) aresubstantially elongated over the length of the rough cylinder.
 33. Thedevice according to claim 32, wherein the relief patterns (13) areessentially filiform and of a height comprised between 1 mm and 15 mm.34. A method for spreading a layer (4) of a bituminous coating over aground (2) to be covered, wherein, in a first time, the bituminouscoating is rolled to make a bituminous coating film (6) of determinedthickness (e) over a determined width and remote above the ground, and,in a second time, said film is crumbled (5) and the bituminous coatingof the crumbled film is made to fall down to the ground, wherein thebituminous coating film of determined thickness (e) is made over anupstream part of an extended roll (8, 9, 10) consisted of an endlessbelt (8) extended between an upstream inner roll (10) and a downstreaminner roll (9), and wherein a rough cylinder (12) including reliefpatterns (13) is implemented opposite the downstream inner roll tocrumble (5) the film (6) made on the endless belt (8).
 35. The methodaccording to claim 34, wherein a bituminous coating is used, which ischosen among: a hot coating having a fabrication temperature higher than150° C., a warm coating having a fabrication temperature higher than100° C. and lower than 150° C., a half-warm coating having a fabricationtemperature between 85° C. and 100° C., a half-cold or cold coatinghaving a fabrication temperature lower than 85° C.
 36. The methodaccording to claim 34, wherein a bituminous coating is used, whosevalues d and D of the d/D ratio are chosen among: a value of 0-2-4 or6.3 mm for d and a value of 4-6.3-10-14-20 mm for D.